Multiple control for brake mechanism



1951 B. L. LONNGREN 2,569,479

MULTIPLE CONTROL FOR BRAKE MECHANISM Filed July 30; 1948 2 Sheets-Sheet 1 INVENTOR, BY W fly B. L. LONNGREN MULTIPLE CONTROL FOR BRAKE MECHANISM Oct. 2, 1951 2 Sheets-Sheet 2 Filed July 30, 1948 INVENTOR,

Patented Oct. 2, 1951 UNITED srsrss ATENT OFFICE MULTIPLE 'CONTROL FOK BRAKE I 'MECHANISM V Bruno L. Lonng'ren, South Milwaukee, Wis., as .signor to Bucyrus -Erie Company, South Mllwaukee, Wis a corporation of Delaware Application July 30, 1948, Se'rial No. 41,641

11 Claims. (01. 188-405) rMy invention relates totnew"andrusefuleimprovements in brakes and'contr'okmechanisms therefor, more particularly to control :mechanisms of hydraulic or pneumatic-brakes. J

Although usefulin other relations, this-invention may be employed to'particular advantage'in the control of poweriexcavatoracranes and the like. l

The principal objects of'my invention are to provide. brake control -means such that:

1(1) The brake is automaticallyset'when the fluid or other'normal actuating means fails to two-way to a one-way brake and vice 'ver'sawith- I'Ollt. any addition or substitution of" elements.

In addition to the objects above stated, I-have worked out a'numberoi" novel and usefiil details, which will be readily: evident as the description progresses. l 1

My invention consists in the novel partsiand in the combination and arrangement thereof, which are defined in the appended-claims, of which on'e embodiment is exemplified in the accompanying drawings, which are hereinafter particularly described and explaine'dr vThroughout the description,'the same refer- '-ence number-is applied to 'the same member or to similar members. I

Referrin now to theaccompanying drawings, it'will be seen that: s

Figure. 1 is'a-general' side elevational viewof a band-type brake with control mechanism constructed in accordance'with the'present:irivention.

Figure 2 is an end elevation; taken along the line '2--2 of Figure 1'. i r

Figure 3- is a-vertical-xsection; taken along the line 3-3 of Figure 2', showing the means-forbrak- 1 ing clockwise rotation. of ;thedrum.

Figure 4 is a schematic plan'view. showing the operating valves and pneumatic circuit 'for' 'the brake-control cylinders. 7

Referring nowto Figures l to 3,'we see that'on frame No is mounteddrum i2 over which passes a brake-band i3 oneend of: which is securedas 'atrrockg shaft M, to frame -Ha, while the'other .end is -secured,sas ail/l5, to lever is which is pivend, as at pin I! (see Figure 3),lever l6 ls adapted to be moved by piston rod loofoperating cylinder l9 which is pivotally mounted at :20 on cylindersupport '2 Ion base 'i l. When .the piston rod l8 moves downwardlyunder pressure in the cylindenchamber, lever It 'moves tos'etthe brake (clockwise :ro'tation of lever' l 6" about rock shaft 14). "Compressionspri'ng 22, also mounted on support 2 I acts on rod 23 which is secured to lever 1 5 at 24 adjacent piston [8,to urgetlie lever 16 to brake-releasin position (counterclockwise rotation of lever is about rock shaft 14). Cylinder is is a conventional single a'cting air cylinder supplied with compressed air from a conduit 25 '(Figure'z) vwhich leads to a: control val-ve'hereinafter described;

" It will be noted that counterclockwise:rotation ofdrum l2 tends to release the'brake; since tension in brake band l3 tends to rock lever 16 into brake-releasing position (even against the brakesetting-force of piston! 8) whereas clockwise r0"- tation of drum 1 2 tends to set the brake (Working with piston is to overcome spring 22-). Hence, if only the cylinder-piston assembly 18- 49, which exerts only clockwise tension on the brake band,

is used,--thebrake acts as a one-way brake, be-

ing efiective to brake only clockwise rotati'on bfdrum l2.

To make the above-described one-way brake also effective as atwo way brake, Iemploy' a second cylinder-pistonassembly and lever to exert counterclockwise tension on the brakeband. as will now be described (see Figure 1). -Adja- 'cent the dead-endedportion of brake band 43; le- "ver 26 is pivotally connected at its end 27 to rock shaft 28 on'main frame Ila. Connecting rod' 29 is secured at its lower end to lever 25' as at 3 adjacentend 21, and'has at its upper'endan ad- Jjustable crosshead 3'l'which is adapted 'tobear against lug 32 on brake band [3' and to exert band; when le'ver 28' is urged counterclockwise to eset the brakeJ Stop 2 In (Figure 3) se z'rves through lever iS,'to'dead-'end the band l3gwhen thedrum l2 rotates" counterclockwise. Thecylnoted onframe I la; as atirock shaft". Atits inder 35 is' a'eonventional single-'acting 'air cyi- 3 inder supplied with compressed air from conduit 40 which leads to a control valve as hereinafter described.

Turning now to Figure 1 to 3, we see that the safety control for the brake consists of a heavy spring 4| (Figures 1 and 2) mounted on support 2| and capable when released of setting the brake through spring washer 42, rod 43, bell-crank arm 44, bell-crank shaft 45 (Figure 2) and bell-crank arm 45 (Figure 3) which when released bears down on pin H at the end of brake lever l6 to set the brake. Spring 4| is, however, normally held compressed by rods 41 of a conventional singleacting air-brake cylinder 48 having a piston (not shown) preferably, though not necessarily, of diaphragm type. Rods 41 are fixed to the cylinder 48 which moves upwardly to compress spring 4|, when piston rod 41, which is attached to sup port 2|, is extended under air pressure. When the air supply fails, or when air is intentionally cut off (as when the machine is not in use), spring 4| is released to active position causing the brake to set.

Referring now to Figure 4, we see one of several possible circuits for controlling the pistons of cylinders I9, 35 and 48. Air to both cylinders 18 and 35 is supplied throughconventional compensating valve 49 from pressure chamber 52, and to cylinder 48 through separately-controlled valve 50. When compensating valve 49 is in closed (brake released) position, exhaust from cylinders|9 and 35 passes out through outlet 53 which is automatically closed when valve 49 is opened (to set the brake). Valve 5| between cylinders l9 and 35'operates, when open, to per- 1 mit valve 49 to control both cylinders as a twoway brake, and when closed to permit control of cylinder l9 alone as a one-way brake. Valve 50, normally open during operation, to set the safety brake control in case air pressure should drum; a brake-band frictionally engageable with the drum; first means dead-ending one endof the brake-band against movement in one direction when the drum pulls the brake-band in that direction; first actuating means operatively connected to the other end of the brake-band for setting and releasing the brake-band; second means, independent of said first actuating means, dead-ending said other end of'the brake-band against movement in the opposite direction when the drum pulls the brake-band in said opposite direction;v and second actuating means operatively connected to said one end of the brakeband for setting and releasing the brake-band.

2. A brake according to claim 1, further characterized by having means interconnecting the first and second actuating means for selective operation of one or both of said first and second actuating means.

3. A brake according to claim 1, further characterized by the fact that each brake actuating means includes a fluid operated cylinder-piston assembly, said cylinder-piston assemblies having normally interconnected pressure chambers.

4. In a brake, the combination of: a brake drum; a brake-band for friction engagement with 4 the drum; normally released first brake-setting means operatively connected with a live end of the brake-band; first fluid pressure means to actuate the first brake-setting means to set the brake; normally set second brake setting-means operatively connected to the live end of the brakeband; second fluid pressure means to actuate said second brake-setting means to unset the brake; a common fluid pressure source for the two fluid pressure means; a fluid pressure conduit to connect the source at will to the first fluid pressure means; and a fluid pressure conduit normally connecting the source to the second fluid pressure means; whereby failure of the pressure supply of the first fluid pressure means will permit the second brake-setting means to set the brake.

5. A brake according to claim 4, further characterized by the fact that the first brake-setting means is spring released and that the second brake-setting means is spring set.

6. A brake according to claim 4, further characterized by having means to disconnect the source at will from the second fluid pressure means, whereby the second brake-setting means can be locked in set position when the brake system is not being operated.

7. In a brake, the combination of a brakedrum; a brake-band frictionally engageablewith the drum; first means dead-ending one end of the brake-band against movement in one direction when the drum pulls the brake-band in that direction; first actuating means operatively connected to the other end of the brake-band for setting and releasing the brake-band} second means dead-ending said other end of the brakeband against movement in the opposite direction when the drum pulls the brake-band in said opposite direction; second actuating means operatively connected to said one end of the brakeband for setting and releasing the brake-band; and means interconnecting the first and second actuating means for selective operation of one or both of said first and second actuating means.

8. In a brake, the combination of: a brake drum; a brake-band frictionally engageable with the drum; means dead-ending one end of the brake-band against movement in one direction when the drum pulls the brake-band in that direction; first brake-setting means for setting the brake by motion of the other end of the brakeband to hold the drum against movement in said direction; a fluid-operated cylinder-piston assembly for actuating said first brake-setting means; means dead-ending said other end of the brake-band against movement in the opposite direction when the drum pulls the brake-band in said opposite direction; second brake-setting means for setting the brake by'motion of said one end of the brake-band to hold the drum against movement in said opposite direction; and a second fluid-operated cylinder-piston assembly for actuating said second brake setting means; said cylinder-piston assemblies having normally interconnected pressure chambers.

9. In a brake, the combination of: a brake drum; a brake-band frictionally engageable with the drum; means. dead-ending one end of the brake-band against movement in one direction when the drum pulls the brake-band in that direction; first brake-setting means for setting the brake by motion of the other end of the brakeband to hold the drum against movement in said direction; means dead-ending said other end of site direction when-the drum pulls the brakeband in said opposite direction; and second brake-setting means for setting the brake by motion of said one end of the brake-band to hold the drum against movement in said opposite direction; said second brake-setting means comprising means which is adaptable to engage the brake-band adjacent said one end thereof but is normally out of engagement therewith, and means for actuating said engaging means to tighten said band by moving said one end thereof in said opposite direction; and the secondmentioned dead-ending means comprising stop means for said other end of the band, said stop means being brought into engagement by motion of said other end of the band in said opposite direction.

10. A brake according to claim 9, further characterized by the fact that the first-mentioned dead-ending means is a slip connection, to permit brake-setting movement of said one end of the band when said other end of the'band is dead-ended by the second-mentioned deadending means.

11. In a brake, the combination of: a brake drum; a brake-band for frictionalengagement with the drum; a slip connection for dead-ending one end of the band against movement in one direction when the drum pulls the band in that direction; a pivoted rocker-arm, on which the other end of the band is pivotally anchored; means to rock this arm to set or release the brake by motion of said other end of the band, whereby to hold or release the drum against or for rotation in said one direction; stop means for the rocker-arm for dead-ending said other end of the band against movement in the other direction when the drum pulls the band in said other direction; a contact member on the band adjacent its said one end; a second contact member normally out of engagement with said first contact member; and means to cause said second contact member to engage said first contact member and apply pressure thereon to move said one end of the band in said other direction to hold the drum against rotation in said other direction.

BRUNO L. LONNGREN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,646,718 Wilkinson et a1. Oct. 25, 1927 2,384,346 Schnell Sept. 4, 1945 

